In operating a work vehicle, such as a backhoe, the operator controls a plurality of work operations through manipulating various control levers that control the positioning of hydraulic control valves. The hydraulic control valves in turn regulate the flow of hydraulic fluid to hydraulic cylinders that manipulate the work implement. When operating the backhoe, the operator turns his seat to face rearward. The operator uses control levers to manipulate the boom relative to the tractor, the dipperstick relative to the boom and the bucket relative to the dipperstick.
On some backhoes the operator controls the backhoe by operating two control levers. Such a backhoe is disclosed in U.S. Pat. No. 6,481,950, herein incorporated by reference. The control levers extend upwardly through a control console located in the rear of the operators cab. The control levers are operatively coupled to a control linkage that manipulates hydraulic control valves in response to movement of the control lever. In the above described control configuration, each control lever controls two hydraulic control valves. Each hydraulic control lever controls one backhoe function by extending and retracting the appropriate hydraulic cylinder or cylinders.
In one control configuration, fore-and-aft movement of the left hand control lever lowers and raises the boom. This movement is sometimes referred to as “boom.” Side-to-side movement of the left hand control lever moves the boom side-to-side. This movement is sometimes referred to as “swing.” Fore-and-aft movement of the right hand control lever pivots the dipperstick relative to the boom. These movements are sometimes referred to as “crowd.” Side-to-side movement of the right hand control lever curls and uncurls the bucket relative to the dipperstick. This movement is sometimes referred to as “curl” or “bucket.” This overall operating pattern is referred to as a “backhoe pattern” as shown in FIG. 5.
On other backhoes, the operator controls the backhoe by operating two control levers, but the control functions corresponding to the fore and aft movements of the right and left control levers are reversed. In this control configuration, fore-and-aft movement of the right hand control lever lowers and raises the boom. Side-to-side movement of the right hand control lever remains the same, it curls and uncurls the bucket relative to the dipperstick. Fore-and-aft movement of the left hand control lever pivots the dipperstick relative to the boom. Side-to-side movement of the left hand control lever remains the same, it moves the boom side-to-side. This overall operating pattern is referred to as an “SAE pattern” or “excavator pattern” as shown in FIG. 5.
Although it is possible to purchase a backhoe with the operating pattern of choice, the operating pattern cannot be easily changed in the field. Furthermore, some backhoe owners employ several operators who share the use of one backhoe and each operator may be accustomed to a different operating pattern.
Some heretofore known backhoes have had the capability to switch between patterns. But such switching requires the operator to leave the vehicle cab and, using a wrench, loosening a retaining bolt, turning a switch lever and then retightening the retaining bolt, to switch patterns. The switch lever is located behind a rear tire in a location exposed to dirt and mud.
The present inventors have recognized that to increase the utility of a work vehicle, it would be advantageous if different operators accustomed to different operating patterns of the work vehicle controls could select their preferred control pattern easily and quickly. The present inventors have recognized that it would be advantageous to provide a pattern switching arrangement that was more easily operable without requiring an operator to leave the operator's cab to make a pattern switch and without requiring the use of a tool to switch patterns.